1. Field of the Invention
The present invention relates to a radiation image capturing device, and a radiation image capturing system. In particular, the present invention relates to a radiation image capturing device, and a radiation image capturing system, that capture radiation images expressed by radiation that has passed through an object of image capturing.
2. Description of the Related Art
Radiation detectors such as FPDs (Flat Panel Detectors), in which a radiation-sensitive layer is disposed on a TFT (Thin Film Transistor) active matrix substrate and that can convert radiation directly into digital data, and the like have been put into practice in recent years. Portable radiation image capturing devices (hereinafter also called “electronic cassettes”), that capture radiation images expressed by irradiated radiation by using such radiation detectors, have been put into practice. As methods of converting radiation in radiation detectors used in the electronic cassettes, there are an indirect-conversion method that converts radiation into light at a scintillator and thereafter converts the light into charges at a semiconductor layer of photodiodes or the like, and a direct-conversion method that converts radiation into charges at a semiconductor layer of amorphous silicon or the like, and the like. In these respective methods, there are various materials that can be used at the semiconductor layer.
In the case of capturing video images at this type of radiation image capturing device, the amount of heat that is generated is large as compared with a case in which still image capturing is carried out. As a result, the need to improve the cooling function arises, the size of the device increases, and the portability thereof deteriorates.
Examples of reasons why the amount of generated heat is greater in video image capturing than in still image capturing are: because image capturing is carried out continuously, the amount of heat generated per unit time at the electric circuits for carrying out voltage conversion and the power supply section that includes an incorporated battery is large, and the time period over which heat is generated is long; and, because it is necessary to improve the processing ability of the electric circuits that carry out image processing in real time on the image information obtained by video image capturing, there is the need to use circuits whose amount of generated heat is great (circuits whose frequency of the clock signals used for synchronous control is high or whose circuit scale is large) as compared with electric circuits that are used for still image capturing.
Japanese Patent Application Laid-Open (JP-A) No. 2005-181922 discloses an X-ray image capturing device that detects X-rays that have passed through a subject by a planar X-ray detector. The X-ray image capturing device has a housing that incorporates the planar X-ray detector therein, and a cooling unit that suppresses a rise in temperature of the housing interior. The cooling unit is structured so to as to be detachable with respect to the exterior of the housing.
JP-A No. 2007-44068 discloses an image capturing device having a solid-state pickup element that is sensitive to X-rays. The image capturing device includes a pickup unit that receives X-rays and converts the received X-rays into image signals, a control unit that carries out control of the image capturing device including the image capturing using the pickup unit, and a communication unit having at least two or more communication interfaces for outputting the image signals acquired at the pickup unit.
JP-A No. 2007-127414 discloses a radiation image detector that detects radiation irradiated toward a subject and acquires radiation image information. The radiation image detector is provided with two or more structures among the following structures: a communication section that transmits the image data of the radiation image to an external device; a connection terminal that is connected either directly or indirectly to the external device and is for transmitting the image data of the radiation image to the external device; a storage unit that is detachable and that stores the image data. The radiation image detector also has a control section that judges whether the image data of the radiation image is to be transmitted from the communication section, or is to be transmitted from the connection terminal, or is to be transmitted from the storage unit. On the basis of the results of this judgment, the control section switches the method of transmitting the image data of the radiation image to the external device.
JP-A No. 2005-6979 discloses a radiation image capturing device having, at a device main body: a battery; a digital image capturing section that captures a radiation image as a digital image; a wired communication section that transmits and receives digital image data or image capturing control signals via a cable to and from the exterior of the device main body; a wireless communication section that wirelessly transmits and receives digital image data or image capturing control signals to and from the exterior of the device main body without going through a cable; a connection sensing section that senses connection of the cable to the device main body; a communication selecting section that selects, on the basis of the results of sensing of the connection sensing section, which of the wired communication section and the wireless communication section is to carry out transmitting and receiving of the digital image data and the image capturing control signals; and a power supply selecting section that selects, on the basis of the results of sensing of the connection sensing section, whether or not the battery is to be used as the power supply of the device main body.
JP-A No. 2002-199388 discloses an X-ray image capturing device formed from: a two-dimensional array sensor that receives an X-ray image; a drive unit that drives the sensor in accordance with control signals originating from an X-ray generating device; an amp unit that, by the drive unit, selects matrices within the sensor and amplifies the data of the respective matrices; an AD unit digitally converting the output from the amp unit; a unit that serializes the image data that has successively been digitalized at the AD unit and the drive unit; an X-ray image capturing section that is structured from a transfer unit that transfers the serialized image data; a unit that de-serializes image data transferred by the transfer unit; and a PC for control that is structured from a unit that disposes the de-serialized image data within a frame memory. The transfer unit, that transfers signals between the X-ray image capturing section and the PC for control, is a transfer unit formed from an optical fiber cable that transfers optical signals obtained by converting the serialized image data from electricity to light, and a metal cable that transfers control signals that originate from the X-ray generating device and the PC for control, or that the drive unit response-originates.
JP-A No. 2005-470 discloses an X-ray image capturing device that irradiates X-rays that are generated by an X-ray generating unit onto a subject, and detects, at a sensor, the X-ray distribution that is transmitted through the subject. The X-ray image capturing device has: an X-ray detection unit having a detection surface at which plural detecting elements are disposed two-dimensionally; an X-ray irradiation unit that irradiates X-rays with respect to the X-ray detection unit; a first supporting mechanism that supports the X-ray detection unit; and a second supporting mechanism that supports the X-ray irradiation unit. The X-ray detection unit is detachable with respect to the first supporting mechanism. The X-ray detection unit has a control unit such that images can be captured in a state in which the X-ray detection unit is separated from the first supporting mechanism. The second supporting mechanism has a moving mechanism that, in a state in which the X-ray detection unit is fixed to the first supporting mechanism, fixes the X-ray irradiation unit in a first direction facing the X-ray detection unit, and, in a state in which the X-ray detection unit is separated from the first supporting mechanism, enables the X-ray irradiation unit to irradiate X-rays in other than the first direction.
JP-A No. 2008-83031 discloses an electronic cassette type radiation detecting device having a sensor array that includes plural sensors that detect incident radiation. The electronic cassette type radiation detecting device has a connection section that connects with an additional function module that is detachable, and has a selection unit that, due to the additional function module being connected, switches to a state in which the image capturing mode can be selected from among still image capturing and video image capturing.